Cam controlled pulse transmitter



y 1949. L E. BODMER 2,469,761

CAM CONTROLLED PULSE TRANSMITTER Filed June 18, 1945 s Sheets-Sheet 1 May 10, 1949. E. BODMER 2,469,751

cm comnomxsn PULSE TRANSMITTER 7 Filed June 1a, 1945 s Sheets-Sheet 2 May 10, 1949.

E. BODMER CAM CONTROLLED PULSE TRANSMITTER s sheets-sheet 3 Filed June 18, 1945 [massif Bodnz er Patented May 10, 1949 UNIT ED S TAT ES PATENT OFFICE Ernest Bodmer, Grand-Lancy-Geneve, Switzerland Application June 18, 1945, Serial No. 600,115 InSwitzerland August 21, 1944 1 2 Claims.

There exist various record actuated devices for transmitting control signals in the form of electric impulses. Certain of these devices comprise a rotary member moving a perforated endless, ribbon or a perforated drum, and rubbing contacts put on the drum, or a light source with photorelectric cells. When a contact registers With a perforation in the ribbon, or when a ray of. light. passes through a perforation, it causes an electric circuit to close which in general energises an electro-magnetic relay.

These devices are much used and offer advantages in the case where they control, for instance, a machine which must always carry outthe same cycle of operations. Such devices are. also advantageous when the machine must perform a limited number of cycles of different operations. But whenv the machine must carry out a greatnumber of. different cycles of onerotions or. even when a particular cycle of one tions is only used for a short limited time and never used again, it is evident that these devices no. longer comply with. practical requirements. In fact, for each such cycle of operations it is necessary to perforate a new ribbon, an operation whichentails too much work in comparison. with the little time that the ribbon will be used;

Besides that, for cycles of operations extendingi over a very long period of. time and comprising operations of very briefduration, it is practically impossible to avoid an undesired repetition of such operations of brief duration, since theoperation is-terminated before the perforation has advanced far enough. to prevent a. new

The subject matter of the present invention is a device for transmitting control signals the form of electric impulses, which tends to eli... inate the drawbacks mentioned above, by the fact thatit is composed of several rotary members, each. of which is rotated by one. common shaft by means of lock-bolts fixing the angular positions of each rotary member with respect; to the others, and by the fact that each rotary member includes at least one part intended for the control of an electric circuit.

Another object of the invention is to provide a keying part intended to control an el.ectric=c ir cuit, which has a keying cam having av short dwell so arranged as to cause the transmission of a single current impulse of short durationine the electric circuit. Further this keying part may cooperate with the control member of an electric contact and may be constituted by. a port or slit, allowing the rays emitted by a source of light to pass through and impinge on a photoelectric cell. Furthermore, this port or. slit may cooperate with a control member, mechanically connected to an electric contact by means of. a flexible coupling.

Still another object of the present invention is a device, in which the lock-bolts for fixing; the rotary members may each be provided with a control member and may be displaceably mounted in bores provided in parts rigidly fixedto the shaft, each lock-bolt being urged by a. spring tending to keep it in engagement with teeth carried by the discs, and each disc carries a graduated scale, which can be moved with respect to a register mark provided on a part rigidly connected to the shaft.

The accompanying drawing shows diagrammatically and by way of example two forms of embodiment of the subject matter of the present invention.

Fig. 1 is a View of one form of the invention in perspective with parts broken away;

Fig. 2 is a partial side view of the embodiment of Fig. 1 with parts in section of the embodiment of Fig. 1;

Fig. 3 is a side view of a modified form with parts in section;

Fig. 4 is a front view or the form of Fig. 3.

In the form of embodiment shown in Figs. 1 and 2 of the drawing, the device comprises. an.- nular discs I, freely rotatably mounted on a hub 2 rigidly connected to a shaft 2a. Each. disc carries a graduated scale 3 which is mounted to move past a register mark 4. This latter is stamped on a part rigidly connected to the hub 2. Each disc I is rotated by the shaft 2a by means of a lock-bolt 5 urged by a spring 8 tend,- ing to keep it in contact with the internal teeth 8, of disc lv whose pitch corresponds to the graduation of the scale. Each locking bolt carries a button or operating. member 1.

In the form of embodiment shownin Figs.

1 and 2 the locking-bolts and the operating members are mounted in bores provided in shoulders 53 which are carried on the hub 72, while each disc carries internally a set of teeth 6. In a modified form of the device, the teeth may be rigidly connected to the shoulders, while the lock bolts and operating members can be mounted in bores provided in the discs.

Each disc has on its periphery a notch 10 with which a finger I! cooperates; the finger is pivoted on a pinion 12 parallel to the shaft 2a.

This finger H is subjected to the action of a spring tending to make it enter the notch Iii. The angular rotating displacements of this finger H upon falling into a notch ill control the displacements of a rod 13. For this purpose, the finger H carries an arm [4, in a bore of which is slidably mounted a rod 15, urged by a Spring 16 (Fig. 2). This rod 15 carries a roller ll. The latter is pressed by the spring l6 against the rod l3 which slides in a bore at right angles to the axis l2 in a support 18. This rod 13 carries a contact l9, connected to a source of electricity (not shown) and is urged by a Spring 20 tending to withdraw the contact [9 from a second contact-piece 2| connected to the source of electricity. The rod 13 has a shoulder 22 which, in the normal position (the position shown), rests on the roller H.

The device described above works as follows:

When the shaft 2a is rotated clockwise, the discs I are rotated by the lock-bolts which are engaged with the teeth 6 on the inner periphery of disc 5. When the notch of a disc I passes under a finger i i, the latter falls first on a step or dwell 23. This movement of the finger ll causes the rod 3 to be urged upward against the force of its spring 20. The movement of the rod I3 is sufficient to close the contact l9-2l and thus allow a current to flow in the circuit which it controls. The shaft 2a continuing its movement, the finger l I then slips off the step 23 and falls further to the bottom of the notch ID. The contact 2! opposing a further displacement of the rod E3, the roller ll slips up over the shoulder 22 and the rod 13 is withdrawn by its spring 20. This displacement of the rod I3 causes the contacts I 92! to separate and the current to cease to flow in the circuit which they control. A stop 25, whose position can be adjusted, limits the downward movement of the rod !3. Thus an order has been issued in the form of an impulse of electric current.

The shaft continuing to rotate, the finger H is pressed back against the action of its spring by a sloping surface 24 which extends from the bottom of the notch Hi to the circumferential periphery of the disc. The position of the adjustable stop 25 is chosen in such a way that, when the finger H slides along the circumferential periphery of the disc, the roller !7 is brought back onto the face of the shoulder 22 which is remote from the contact IS (the position shown in the drawing) In order to facilitate the passage of the roller ll from one side of the shoulder 22 to the other, the faces of the shoulder 22 are sloped, being the sides of cones. To allow the roller H to pass on to the face of the shoulder 22 away from the contact i9, it is suificient for the stop 25 to be adjusted in such a way that when the finger II is riding along the circumferential periphery of the disc I, the plane passing through the axis of the roller l1 and at right angles to the rod I3 4 is situated on the side of the shoulder 22 away from the contact 19.

Since each disc can be set in the desired an-- gular position with respect to the shaft 2a, it is easy to see that this device allows a current impulse to be sent in the course of one revolution of this shaft at the desired instant in each of the electric circuits controlled by a pair of con tacts as 2l-|9. Each disc allows an order to be sent for performing one operation.

The device comprises as many rotary discs as the cycle of operations comprises separate operations to be performed. The angular velocity of the shaft carrying the discs is chosen in such a way that this shaft makes one complete revolution in the period of time corresponding to the duration of a complete cycle of operations.

It is evident that the notches made in the discs may be replaced by projections.

In the modified form of th invention. shown in Figs. 3 and 4, the device comprises a plurality of discs arranged concentrically to each other and each provided with a notch or a projection on one of their lateral faces.

In one modified form, each disc is hollowed out and one of its sides has a port or slit. allowing rays from a lamp to impinge on a photc-electric cell at a desired instant in order to control an electric circuit.

It is to be noted that, owing to th fact that the register marks 4 are fixed with respect to the hub 2, which itself is fixed to the driving shaft, while the graduated scales are located on the discs, the adjustment of the relative positions of the discs with reference to each other be effected very easily and rapidly, provided that the register marks are situated so that they can all be seen at the same time. In fact, the adjusting of all the discs can then be effected for the same angular position of the driving shaft. The arrangement also allows of very easy checking of the setting of the discs.

From what has been said, it can b seen that to prevent the undesired repetition of an operation of very short duration. it is sufficient to make the step 23 so short, that the finger falls to the bottom of the notch before the of the shortest operation. In other words, the angular length of this step must be smaller than the angular displacement of the rotating member during the time taken by the most rapid operation of the cycle of operations.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. In a sequence switch, a pair of contacts, contact closing means normally in the open. position and adapted to close said. content" c cam disc have a peripheral cam surface, sai intact closing means comprising cam engaging means engageable with said surface, a t, hub fixedly carried on said shaft, and freel rotatably carrying said disc, and adjustable engaging means carried by said hub and with said disc for adjustably determilnng the angular position of said disc on said hub, said bolt adjustable engaging means comprising carrying a detent and being radially ably received within a radial bore of a of said hub and resilient means for r: urging said bolt radially outward, and said disc comprising an internal toothed rack adapted to lockingly receive said detent in a selected one of its teeth, said cam surface having a first short step dwell and a second step dwell successively more remote from the periphery of said disc, and said contact closing means comprising a contact carrying element and means actuatable by said cam engaging means and adapted to displace said element into contact closing position when said cam engaging means engages the first step dwell of said cam surface, and to release said element from contact closing position into starting position when said cam engaging means engages said second step dwell of said cam surface, the length of said first short step dwell corresponding to the desired length of closing of said contacts.

2. In a sequence switch, a pair of contacts, contact closing means normally in the open position and adapted to close said contacts, a cam disc having a peripheral cam surface, said contact closing means comprising cam engaging means engageable with said cam surface, a shaft, a hub fixedly carried on said shaft, and freely rotatably carrying said disc, and adjustable engaging means carried by said hub and engageable with said disc for adjustably determining the angular position of said disc on said hub, said adjustable engaging means comprising a bolt carrying a detent and being radially displaceably received within a radial bore of a shoulder of said hub and resilient means for normally urging said bolt radially outward, and said disc comprising an internal toothed rack adapted to lockingly receive said detent in a selected one of its teeth, said cam surface having a first short step dwell an a second step dwell successively more remote from the periphery of said disc, and said contact closing means comprising a contact carrying rod, means for normally urging said rod into the open contact position, a doubly beveled shoulder carried by said rod, and shoulder engaging means displaceably carried by said cam engaging means and resiliently urged into engagement with said shoulder, said rod and its shoulder and said shoulder engaging means being so positioned that said rod is displaced into contact closing means when said cam engaging means engages the first step dwell of said cam surface, and said rod is released from contact closing position into starting position by the passage of said shoulder engaging means over said shoulder when said cam engaging means engages said second step dwell of said cam surface, the length of said first short step dwell corresponding to the desired length of closing of said contacts.

ERNEST BODMER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,851,247 Hall Mar. 29, 1932 1,880,105 Reifel Sept. 27, 1932 1,989,522 McWhirter Jan. 29, 1935 2,243,088 Clark May 27, 1941 2,394,142 Breckenridge Feb. 5, 1946 

